Call to a member function diff() on null

[puspjoshi]

Prerequisites

• Able to reproduce the behaviour outside of your code, the problem is isolated to Laravel Excel.
• Checked that your issue isn't already filed.
• Checked if no PR was submitted that fixes this problem.

Versions

• PHP version: 8.0
• Laravel version: 8.70.2
• Nova version: 3.29
• Package version: Nova 1.X

Description

While exporting to csv/xlsx computed field does not work with laravel diff between updated and created date format.

Steps to Reproduce

In nova resource my code is:

In table all working properly :

But while exporting im getting null on diff. :

Expected behavior:
I want to export that computed field(updated_at - created_at)

Actual behavior: